Automated media storage libraries are known for providing cost effective access to large quantities of stored media. Generally, media storage libraries include a large number of storage slots on which are stored portable data storage media. The typical portable data storage media is a tape cartridge, an optical cartridge, a disk cartridge, electronic storage media, and the like. By “electronic storage media,” Applicants mean a device such as a PROM, EPROM, EEPROM, Flash PROM, compactflash, smartmedia, and the like.
One (or more) accessor(s) typically accesses the data storage media from the storage slots and delivers the accessed media to a data storage device for reading and/or writing data on the accessed media. Suitable electronics operate the accessor(s) and operate the data storage device(s) to provide information to, and/or to receive information from, an attached on-line host computer system.
Tape storage media, i.e. magnetic tape, is subject to variability. Such variability includes, for example, inconsistencies between manufacturers of that media. In addition certain tape media comprises encoded information using, for example, a (0,k) modulation code. Other tape media comprises, for example, encoded information using a (1,7) modulation code. Some tape drives may have to read media with either type of modulation code. In addition, such variability arises from modernization of the media.
In order to minimize the effects of such media variability, what is needed is an apparatus and method to dynamically adjust the read channel architecture used to first calibrate the read channel to identify the phase and frequency of the information encoded on the tape, and to then accurately read that information.